In recent, fatty acid esters of a polyglycerine are permitted as an additive such as an emulsifier for food-stuffs, and demands in a market are getting increased. The fatty acid esters composition of a polyglycerine have been usually employed in a variety of fields, particularly such as foods, as an emulsifier or an agent for adjusting a viscosity because esters having a wide range of HLB values can be obtained by the combination of polyglycerines having various molecular weight with fatty acids having various chain length which are starting materials, and it exhibits a higher stability in an acidic range.
As processes for preparing the fatty acid esters composition of a polyglycerine, there are exemplified; (1) an esterification reaction of a polyglycerine with a fatty acid, (2) a transesterification reaction of a polyglycerine with a fatty acid ester, (3) a transesterification reaction of a polyglycerine with an oil and fatty acid, (4) an addition polymerization reaction of glycidol to a monoglyceride of a fatty acid, and (5) an addition polymerization reaction of glycidol to a fatty acid, etc. Of the above-described reactions, the processes (2) and (3) are problematic in the reactivity and the processes have many limitations in quality and purity of the fatty acid ester of a polyglycerine.
The process (1) is described in JAOCS (Journal of American Oil Chemists' Society), Vol. 58, page 878 (1981), in which there is carried out the esterification reaction of a polyglycerine with a fatty acid in the presence of alkali catalysts to obtain a fatty acid ester of the polyglycerine.
Furthermore, Japanese Patent Unexamined Publication (Kokai) No. 41007/1994 discloses similar processes.
The process (5) is described in Japanese Patent Unexamined Publication (Kokai) No. 65705/1976, in which there is prepared a fatty acid monoester of glycerine. However, the Publication states that there is obtained a carboxylic acid-1-monoglyceride having the polymerization degree of glycerine of 1 with a high percentage in the presence of an inert solvent, that is, it corresponds to a compound having n of average 1 in the above-described chemical formula [1]. Notwithstanding, there is not mentioned a fatty acid esters composition of a polyglycerine at all in the Publication.
As processes in which the addition polymerization reaction of glycidol is employed, there are exemplified the addition polymerization reaction [Japanese Patent Examined Publication (Kokoku) No. 55254/1989, Japanese Patent Examined Publication (Kokoku) No. 11532/1992, Japanese Patent Examined Publication (Kokoku) No. 1291/1993] of glycidol to glycerine to obtain a polyglycerine employed in the processes (1) to (3), the preparation of a polyglycerine [Japanese Patent Examined Publication (Kokoku) No. 69621/1992] by a hydrolysis reaction after the addition polymerization reaction of glycidol to a fatty acid, and the preparation of polyglycerine monoalkylether or the preparation of polyglycerine monoalkylthioether [U.S. Pat. Nos. 3,821,372, 3,966,398, and 4,087,466], etc.
However, in the preparation process of a polyglycerine by a hydrolysis reaction after the addition polymerization reaction of glycidol to a fatty acid described in Japanese Patent Examined Publication (Kokoku) No. 69621/1992, low fatty acids (a carbon number of 2 to 6) are employed as fatty acids to prepare polyglycerines, and a fatty acid ester of a polyglycerine is not mentioned at all.
Heretofore, a fatty acid monoester of a polyglycerine has been prepared by the above-described process (1). In the process, it is pointed out that a polyglycerine having reactive hydroxyl groups of 4 to 10 on an average is employed as a starting polyglycerine, as a result, a resulting product contains an unreacted polyglycerine, poly-substituted fatty acid esters such as diester, triester, and tetraester, etc. other than the desired fatty acid monoester of a polyglycerine [N. Garti, et al, Journal of American Oil Chemists' Society, 59, 317-319 (1982)].
Furthermore, even in the process (4) in which glycidol is addition polymerized to a fatty acid monoglyceride, a purity of a reaction product remarkably depends upon the starting fatty acid monoglyceride [c.f. U.S. Pat. No. 4,515,775]. Particularly, in the case when there is employed a fatty acid monoglyceride obtained by the reaction of glycerine with a fatty acid as a starting material, the starting material contains unreacted glycerine as well as in the above-described process (1), resulting in that a fatty acid monoester of a polyglycerine obtained by the addition polymerization of glycidol contains only approximately 40% of the fatty acid monoester, and the residue of approximately 60% is composed of unreacted glycerine and poly-substituted fatty acid esters [Shigeru Tsuda, Monoglyceride, page 67 (1985), Maki Book Store].
As described above, there remain a large amount of unreacted polyglycerine and poly-substituted fatty acid esters in the fatty acid monoester of a polyglycerine employed until now. In the case when such the fatty acid monoester is employed as surfactants or emulsion stabilizers in food industries, it results in decrease of surface tension, decrease of dispersibility, decrease of foaming ability, and decrease of stability in emulsifying.
As a process for removing the unreacted polyglycerine, Japanese Patent Unexamined Publication (Kokai) No. 23837/1988 discloses a process in which the unreacted polyglycerine is removed by a liquid separation process using a mixed solvent composed of at least one of water-soluble organic solvents or water and at least one of water-insoluble organic solvents.
Furthermore, Japanese Patent unexamined Publication (Kokai) No. 81252/1991 discloses a process that the unreacted polyglycerine is removed by an adsorption method in which a solution of a reaction product in esterification is brought into contact with an alkyl-silylated silicagel.
Still further, Japanese Patent Unexamined Publication (Kokai) No. 41007/1994 discloses an extracting process in which the unreacted polyglycerine is removed by employing a water-soluble organic solvent such as n-butyl alcohol, n-propanol, or dioxane, etc. together with water or an aqueous solution containing a salting agent such as lithium, sodium, potassium or ammonium salts of an organic acid or an inorganic acid such as sulfuric acid or phosphoric acid.
And also, Japanese Patent Unexamined Publication (Kokai) No. 228052/1994 discloses an extracting process in which the unreacted polyglycerine is removed by employing methylethylketore together with water.
However, the process in Japanese Patent Unexamined Publication (Kokai) No. 23837/1988 includes a problem in uses for food-stuff from a viewpoint of safety because of aromatic hydrocarbons such as benzene and toluene which are described as examples of the water-insoluble organic solvents. Furthermore, in the process, the reaction molar ratio of a fatty acid to a polyglycerine is limited within 1, and there is not described the effectiveness in the reaction molar ratio exceeding 1.
Still further, in the case of a toluene/methanol system, it is observed that a large amount of a fatty acid ester of polyglycerine having a high HLB value moves to methanol phase containing water even in the reaction ratio below 1 and, further, unreacted polyglycerine cannot be sufficiently removed, resulting in that there are problems in industrial preparation.
In addition, the separation process disclosed in the Kokai No. 81252/1991 includes disadvantages that operation costs are expensive and operations are troublesome.
Besides, even though according to the prior arts including the processes disclosed in the Kokai No. 41007/1994 and 228052/1994, although the unreacted polyglycerine can be removed, poly-substituted esters of polyglycerine cannot be removed.
As described hereinabove, in the case when there is prepared a fatty acid esters composition of a polyglycerine according to the above-described processes (4) and (5) in which glycidol is employed, preparation of polyglycerine can be prevented. However, there is a problem that a small amount of unreacted glycidol remains in the fatty acid esters composition of a polyglycerine.
Even a small amount, unreacted residual glycidol itself does not exhibit emulsifying ability, and unpreferably causes a remarkable decrease of surface tension, dispersibility, foaming ability, and stability in emulsifying in products including the fatty acid esters composition of a polyglycerine.
In order to remove a small amount of unreacted glycidol from the composition, there requires molecular distillation which is not economical and not preferred from a viewpoint of industrial applications. It is to be noted that glycidol is another name of an epoxy alcohol.
In view of the above-described background, there has been expected a fatty acid esters composition of a polyglycerine containing high contents of a fatty acid monoester which exhibits an improved surface tension, dispersibility, foaming ability, and stability in emulsifying during uses as an emulsifying stabilizer in the fields of surface active agents, food-stuffs, cosmetics, and detergents.
Furthermore, the fatty acid esters composition of a polyglycerine containing high contents of a fatty acid monoester in the present invention effectively acts as a plasticizer, an improver of a wetting ability for hydrophobic resins, an improver of a printing property, an anti-static agent, a releasing agent, or an anti-clouding agent, etc. for a variety of resins which include a polyvinyl chloride resin, a styrene-based resin, a methylmethacrylate-based resin, and a polyacetal resin.
For example, a polyvinyl chloride resin has been widely employed as a wrapping film or a bottle for food-stuffs, cosmetics, detergents, and other miscellaneous goods, materials for printing such as a calendar and a poster because of its excellent rigidity, transparency, moldability, printing ability.
In particular, uniaxially or biaxially oriented films are employed as a shrinkable wrapping and a shrinkable label because of the excellence in rigidity, a gloss, dimensional stability in storage, and a shrinkable property.
However, similarly to other resins, a polyvinyl chloride resin has a disadvantage that static electricity is very readily charged, resulting in that it gives an unpleasant feeling to human bodies and it readily catches dusts in air.
Accordingly, there is often carried out a process for preventing static electricity.
The process for preventing static electricity includes mixing an anti-static agent together with a thermal stabilizer, a reinforcing material, and a slipping agent, etc. in the case of molding a polyvinyl chloride resin, or coating an anti-static agent after molding.
As the anti-static agent for vinyl chloride resins, there have been conventionally employed a fatty acid ester of glycerine, a fatty acid ester of sorbitan, a non-ionic surface active agent of a higher alcohol, and an anionic surface active agent such as a sodium alkylbenzene sulfonate and a sodium alkylsulfonate. However, mixing of the anti-static agents cannot sufficiently give an effect for preventing static electricity to films having thin thickness such as thermally shrinkable oriented films, and transparency of the films is occasionalLy decreased.
On the other hand, coating of the anti-static agents after molding has disadvantages that an effect for preventing static electricity is often decreased by rubbing or evaporation with a long lapse of time, and further films themselves readily cause blocking.
In JP Kokai No. 1861/1994, although there is disclosed the use of a fatty acid esters composition of a polyglycerine for an anti-static agent, the composition contains a large amount of a residual polyglycerine and poly-substituted esters, unpreferably resulting in that an effect for emulsifying and preventing static electricity is remarkably small, whereby, a large amount of the composition has to be employed.
Meanwhile, a styrene-based resin is excellent in transparency, non-toxic, non-deodorant, and water-resistant.
However, there has been a problem that it is brittle in spite of exhibiting strength and rigidness. Recently, the brittleness in a styrene-based resin has been improved, whereby, the styrene-based resin has been used as films for food-stuffs.
Particularly, the styrene-based resin films have a variety of problems in the use as films for wrapping food-stuffs because of non-affinity for water.
In the case when the styrene-based resin films are used for wrapping food-stuffs and stored at low temperatures, moisture in the food-stuffs such as vegetables or meat forms drops of water over the films. There is a problem that the drops of water adversely affect transparency of the films, unpreferably resulting in that the food-stuffs in wrapping cannot be visually identified, and it is not only visually unpreferred, but also it gives a bad feeling.
In order to solve the problem, there has been thought out a process for improving surface properties of the films.
As the process for improving surface properties of the films, there are known processes that an anti-clouding agent is coated on the films or mixed in preparing the films.
Although the coating process of the anti-clouding agent provides an excellent anti-clouding effect for a short period after coating, anti-clouding effect becomes decreased by rubbing with a long time of lapse.
On the other hand, the mixing process of the anti-clouding agent can provide the films with an excellent anti-clouding effect for a long period after mixing.
As the anti-clouding agent for the styrene-based resin films, there are known (1) fatty acid esters of glycerine (JP Kokoku No. 4147/1963 and JP Kokoku No. 26532/1977), (2) fatty acid esters of polyethyleneglycol (disclosed in JP Kokoku No. 21112/1964), and (3) fatty acid monoesters of polyglycerine (JP Kokai No. 157558/1986), etc.
However, in the case when the fatty acid esters of glycerine of (1) and the fatty acid esters of polyethyleneglycol of (2) are employed as the anti-clouding agent for the styrene-based resin films, a large amount of those must be employed in order to provide an aimed anti-clouding effect, resulting in that mixing is difficult.
In the case when the fatty acid monoesters of polyglycerine of (3) is employed as the anti-clouding agent for the styrene-based resin films, although an anti-clouding effect at ordinary temperatures is excellent, an anti-clouding effect at low temperatures is poor, and further miscibility and transparency are poor, resulting in being not appropriate to wrapping for food-stuffs at low temperatures.
It is to be noted that the fatty acid monoesters of polyglycerine of the above-described (3) are prepared by the esterification of polyglycerine with a fatty acid and the purification by molecular distillation or solvent extraction, which is different from a fatty acid esters composition of polyglycerine in the present invention prepared by the addition polymerization reaction of glycidol to a fatty acid.
Anti-clouding agent for the styrene-based resin films to be employed for wrapping food-stuffs has to be excellent in a low temperature property, a high temperature property, a recovery property, and durability, etc. Particularly, it attaches importance to an anti-clouding effect at a low temperature atmosphere for a long time of period.
In order to make durability of an anti-clouding effect at low temperatures exhibit, an anti-clouding agent to be mixed must exhibit moderate miscibility with the styrene-based resins at Low temperatures.
An anti-clouding agent exhibiting a poor miscibility readily moves to the surface of the film, and it oozes out of the film, unpreferably resulting in causing blocking of the films in spite of the presence of the anti-clouding effect.
On the other hand, an anti-clouding agent exhibiting an excessive miscibility does not readily move to the surface of the film, unpreferably resulting in not exhibiting the anti-clouding effect. Accordingly, an anti-clouding agent must exhibit a well-balanced miscibility with resins.
As a conventional anti-clouding agent for the styrene-based resins has an excessive miscibility with the resins, it is involved inside the resins, resulting in that there has been required a large amount ranging from 7 to 8% by weight.
The problems can be solved by the use of the fatty acid esters composition of a polyglycerine containing high contents of a fatty acid monoester in the present invention.
Furthermore, although an article molded from the styrene-based resin is particularly excellent in transparency, there is a problem that it readily accumulates static electricity induced by friction, and it does not readily disappear, unpreferably resulting in that dust in air is drawn.
In order to prevent the accumulation of static electricity, surface active agents have been mixed in the resin, or silicone-based compounds have been coated on the surface of the molded article.
However, there are problems that a small amount of the surface active agents do not sufficiently provide an anti-static effect and, unpreferably, a large amount of the surface active agents adversely affect transparency of the resin, and coating process of silicone-based compounds onto the surface of the molded article results in increasing costs of production.
The problems can be solved by the use of the fatty acid esters composition of a polyglycerine containing high contents of a fatty acid monoester in the present invention.
In the meantime, a methylmethacrylate-based resin is widely employed in a variety of fields which supply parts for automobiles such as a cover for a variety of meters, optical parts such as photo-magnetic disks and lenses, and a cover for an illuminating lamp, etc., because of its excellence in transparency, weatherability, and mechanical properties, etc.
The molded articles are usually prepared by an injection molding and a compression molding. Particularly, the optical parts such as photo-magnetic disks and lenses are molded by compression molding with a precise mold, and a molded article is exceedingly tightly in contact with the mold, whereby, release of the molded article from the mold becomes insufficient, resulting in making a productivity lower.
Therefore, it is proposed that a variety of releasing agents are employed in molding a methylmethacrylate-based resin.
For example, JP Kokai No. 73754/1086 discloses a methylmethacrylate resin in which there are mixed higher fatty acid esters, polyvalent alcohols, higher alcohols, higher fatty acids, amides of higher fatty acids, and metal salts of higher fatty acids as releasing agents.
However, a releasing property is insufficient, and the releasing agents move to the surface of molded articles, unpreferably resulting in that the surface of the mold becomes dirty, and commercial values remarkably decrease by coloration of the molded article.
The additive which is the fatty acid esters composition of a polyglycerine of the present invention can provide a methylmethacrylate-based resin having an excellent releasing property in spite of a small amount of use.
In the meantime, a polyacetal resin which is one of engineering plastics has been exceedingly widely employed in a variety of fields which supply parts for automobiles or home electric appliances, etc., because of its excellence in physical properties such as mechanical properties and electric properties, moldability, and chemical properties such as chemical resistance and thermal stability.
However, as a polyacetal resin unprocessed is poor in a printing property by a variety of inks, it has been used after a treatment by corona discharge.
However, in the case when it is molded, for example, as a shutter for a disk or a magnetic tape cartridge, as the shutter itself is thin in thickness, bending or deformation is unpreferably caused by a long time treatment or high-voltage treatment in corona discharge, resulting in incapability of practically using.
In view of the situations, there has been expected a material on which inks can be printed even by a short time treatment or low-voltage treatment in corona discharge.
Although a process of a primer coating is known as a process for improving a printing property, the primer process requires solvents, unpreferably resulting in being problematic from viewpoint of environmental pollution.
In JP Kokai No. 195155/1985, there is disclosed a process in which a polyacetal resin is mixed with 0.01-3 parts by weight of hindered amines together with 0.01-4 parts by weight of a specific benztriazole-based ultraviolet absorbent in order to improve weatherability.
However, a printing property cannot be sufficiently improved by the process, and further, durability of the printing property is almost not improved.
Furthermore, in JP Kokai No. 128740/1982, there is disclosed a process in which a polyacetal resin is mixed with 0.01-5 parts by weight of a fatty acid esters composition of a polyglycerine and/or polyalkyleneglycol-alkylether.
However, even a printing property cannot be sufficiently improved by the process because the fatty acid esters composition of a polyglycerine is not prepared by the above-described glycidol process (5).
Still further, in JP Kokoku No. 14709/1994, there is disclosed a process in which a polyacetal resin is mixed with 0.01-3% by weight of a hindered amine compound together with an effective amount (as an anti-static agent) a fatty acid ester of a polyvalent alcohol.
However, even a printing property cannot be sufficiently improved by the process, and further, durability of the printing property is almost not improved.
In addition, in JP Kokai No. 41583/1986, there is disclosed a process in which a polyacetal resin having the thickness of less than 200 microns in skin layer.
However, even a printing property cannot also be satisfactorily improved by the process, and further, durability of the printing property is not occasionally improved.
The problems in the polyacetal resin can be solved by the use of the fatty acid esters composition of a polyglycerine containing high contents of a fatty acid monoester in the present invention.
In addition, there is a problem that polyacetal resins or a article molded therefrom do not exhibit a sufficient wetting property to water and a liquid containing water such as water-soluble inks, and blood, etc.
Wide applications of the polyacetal resins demand a variety of special characteristics as materials. One of the special characteristics is an improved wetting property to inks, etc.
Wetting property is prescribed in JIS K6768 in which it is defined as a condition that liquid coated on the surface of a solid is not repelled.
As a method for measuring the wetting property, there is known a method measuring contact angle, and small contact angle represents easiness of wetting.
Wetting property is required in a variety of molded articles. For example, in an ink jet nozzle in a printer for a personal computer, wetting property of the nozzle edge surface is required in order to constantly control the direction jetting ink, resulting in improving quality of printing.
Furthermore, in a carrier for a biosensor, improved wetting property of a sample liquid is required in order to elevate a sensitivity of measurement.
As methods for improving wetting property, there have been put into practice plasma treatments, chemical treatments, and surface coating by paints. However, the methods include a disadvantage of inferior efficiency in production because a highly-controlled technology is required in order to guarantee a constant quality in surface treatment.
As methods for improving wetting property in a polyacetal resin, although JP-A-257499/1994 discloses a method in which there is mixed an additive such as polyethylene glycol for improving wetting property, the method is insufficient.
Although JP-A-293856/1994 discloses a method in which there is mixed a fatty acid esters composition of a polyglycerine for improving wetting property, a large amount of the composition must be employed in the method because a large amount of unreacted polyglycerine remains in the composition.
Furthermore, a polyalkyleneglycol or a fatty acid esters composition of a polyvalent alcohol is also insufficient from viewpoint of improving wetting property, as shown in Comparative Examples of the present invention which are described later.
Still further, a large amount of a compound improving wetting property occasionally tends to adversely affect to mechanical properties and moldability.
In addition, a polyacetal resin is used as a resin composition by mixing a hindered phenol-based compound, inorganic fibers having short length and other additives, in order to prepare small or precise parts having thin thickness for precision instruments such as a watch, a printer, and a desk top electronic calculator, etc., because of being excellent in mechanical properties and dimensional stability.
As the inorganic fibers having short length, there are exemplified fiberglass and fibrous potassium titanate.
However, the fiberglass has the average fiber diameter ranging from 6 to 13 microns and the average fiber length ranging from 20 to 3000 microns. Accordingly, diameter and length are too thick and too long, resulting in being incapable of employing, for example, as gears for watch having the thickness of 50 or 60 microns.
On the other hand, the fibrous potassium titanate has the average fiber diameter ranging from 0.2 to 2 microns and the average fiber length ranging from 10 to 100 microns.
Accordingly, although the fibrous potassium titanate can be employed as the gears, it often causes a problem of gate plugging in a molding die.
Recently, micro-fibrous titanium oxide has been employed as substitutes for fiberglass and fibrous potassium titanate.
For example, JP-A-113465/1989 teaches that micro fibrous titanium oxide is employed to prepare a resin composition with which there can be formed molded articles having excellent strength and gloss of the surface.
However, the polyacetal resin composition in which micro-fibrous titanium oxide is mixed has a drawback that releasing property from a molding die is poor.
The poorness results in a poor profile property of the surface in a molded article and a stain in a molding die.
Particularly, as the molding die for the precise parts is small, cleaning of the stain requires a long maintenance time, resulting in falling productivity.
The problems can be solved by the use of only a small amount of the fatty acid esters composition of a polyglycerine having high contents of a fatty acid monoester in the present invention.
In the meantime, a fatty acid esters composition of a polyglycerine has been widely used as an additives for cosmetics, toiletries, and detergents.
As a specific example of cosmetics, a water-in-oil type-emulsified composition for cosmetics is used as an agent for keeping moisture on human skin because outer layer is composed of oil components, resulting in being capable of preventing dryness in the human skin.
It is to be noted that a water-in-oil type-emulsified composition for cosmetics is prepared by mixing a water-soluble high viscous compound such as glycerine, oils and/or waxes, water, and an emulsifier, etc.
As it does not have an affinity to water or sweat, properties are not diminished by those, preferably resulting in that the properties are durable for a long time of period.
Furthermore, an affinity to an oily makeup is high, resulting in that it can be preferably employed as an excellent cleansing for the purpose of removing the oily makeup.
However, there are disadvantages that a water-in-oil type-emulsified composition for cosmetics unpreferably gives an oily or sticky feel when it is applied on human skin because outer layer is composed of oil components.
In order to solve the disadvantages, a water-in-oil type-emulsified composition for cosmetics containing a large amount of water has been numerously investigated, for example, as described in JP-B-26366/1985, JP-A-302935/1988, and JP-A-160709/1994.
However, the water-in-oil type-emulsified composition for cosmetics containing a large amount of water is not suitable for the purpose of removing the oily makeup because of high content of water. Furthermore, the water-in-oil type-emulsified composition for cosmetics containing a larger amount of water is not thinly extended.
In the JP-A-160709/1994, it is described that a large amount of silicone oils which are slippery are employed as oil components for outer layer formed by a water-in-oil type-emulsified composition, and further viscosity of the composition is controlled within 20000 cps, whereby, thinness and an oily or sticky feel is improved.
Still further, sorbitan fatty acid esters composition or glycerine fatty acid esters composition which is a lipophilic emulsifier has been employed in the presence or absence of metal soaps of higher fatty acids for preparing the water-in-oil type-emulsified composition for cosmetics. In addition, there are recently employed organic compound-modified clays composition or mixed emulsifiers containing alpha-monoglyceryl ether.
However, in the case when the composition or emulsifiers are employed with a large amount of oils, viscosity thereof exceedingly lowers, resulting in that there cannot be readily obtained a water-in-oil type-emulsified composition for cosmetics having an excellent feel in use and excellent stability for a long time of period.
Besides, there is described a water-in-oil type-emulsified composition for cosmetics having an excellent stability for a long time of period in JP-A-128135/1994 in which a fatty acid esters composition of a polyglycerine is employed. However, the composition is prepared by an esterification reaction of a polyglycerine with a fatty acid which is the preparation process No. (1) described hereinabove.
As described hereinabove, the composition prepared by an esterification reaction of a polyglycerine with a fatty acid has problems.
The problems in the water-in-oil type-emulsified composition for cosmetics can be solved by the use of the fatty acid esters composition of a polyglycerine containing high contents of a fatty acid monoester in the present invention.
As a specific example of cosmetics, a transparent liquid composition for cosmetics has been used as an agent for keeping moisture on human skin, cosmetics for bathroom, cosmetics for cleansing, cosmetics for a massage, cosmetics for a facial pack, cosmetics for hairs, and a base material for medicines, etc.
It is to be noted that a transparent liquid composition for cosmetics is prepared by mixing an non-ionic surface active agent, at least one of water-soluble compound having at least two hydroxyl groups, oils, and water, etc.
The transparent liquid composition for cosmetics usually contains oily components and plasticizers or emulsifiers which are usually non-ionic surface active agents.
It is known that the non-ionic surface active agents are relatively safe for human skin. Recently, the use of a fatty acid esters composition of a polyglycerine is proposed similarly to a fatty acid esters composition of sucrose instead of the non-ionic surface active agents from viewpoint of irritating skin.
However, a conventional fatty acid esters composition of polyglycerine is poorer in a solubilizing and emulsifying property compared to non-ionic surface active agents having polyoxyethylene chains. Particularly, it is difficult to solubilize a large amount of oily components in water which is a base material, and as a composition for cosmetics is highly viscous, there has been a disadvantage that a feel in use is not heavy.
The problems in the transparent liquid composition for cosmetics can be solved by the use of the fatty acid esters composition of a polyglycerine containing high contents of a fatty acid monoester in the present invention.
As a specific example of cosmetics, a gel-like emulsified composition for cosmetics has been used as cosmetics for cleansing and cosmetics for a massage, etc.
It is to be noted that a gel-like emulsified composition for cosmetics is usually prepared by mixing glycerine, oils, a polyvalent alcohol except glycerine, and an emulsifier, etc.
It has been conventionally difficult to prepare a gel-like emulsified composition for cosmetics having a stability because of characteristic properties thereof. In order to prepare a gel-like emulsified composition having a stability, it has been uncommonly tried to make the composition itself high viscous at the sacrifice of a special characteristic and a feel in use.
Furthermore, although a gel-like emulsified composition for cosmetics has been numerously investigated with development of a hydrophilic fatty acid esters composition of a polyglycerine, there is a problem that a conventional fatty acid esters composition of a polyglycerine exhibits an unpleasant feel in use which is a poor spreadability because of its sticky property.
As a method for solving the problem, for example, JP-A-224507/1992 discloses an instance that there are employed a fatty acid esters composition of polyoxyethylenesorbit and/or a fatty acid esters composition of polyoxyethylenesorbit together with a fatty acid esters composition of diglycerine instead of a hydrophilic fatty acid esters composition of a polyglycerine, and JP-A-4911/1993 and JP-A-4912/1993 disclose instances that there are employed natural surface active agents.
However, the compositions are insufficient from a viewpoint of safety, there has been expected the development of a fatty acid esters composition of a polyglycerine having excellent safety, an excellent feel in use, and a special characteristic for a gel-like emulsified composition.
The expectation can be attained by the fatty acid esters composition of a polyglycerine containing high contents of a fatty acid monoester in the present invention.
The problems in the gel-like emulsified composition for cosmetics can be solved by the use of the fatty acid esters composition of a polyglycerine containing high contents of a fatty acid monoester in the present invention.
As a specific example of cosmetics, a composition for tooth paste contains a foaming agent in order to give a refreshing feel, a dispersing and emulsifying function, and a foaming function, and a surface active agent is employed for giving functions.
It is to be noted that a composition for tooth paste is usually prepared by mixing an abrasive such as secondary hydrated calcium phosphate, water-soluble compounds having high molecular weight such as a carboxymethyl cellulose, a wetting agent such as glycerine, and medicinal components, etc.
The surface active agent to be employed for giving functions is an essential component. The refreshing feel in teeth-brushing is enhanced by a decrease of surface tension owing to mixing it. Furthermore, the effect is enhanced by accelerating dispersion and permeation of the medicinal components owing to mixing it. Still further, the surface active agent sensuously gives stability by foaming in use.
As the composition for tooth paste is used in mouth, not only the surface active agent to be employed must possess excellent ability for decreasing surface tension and excellent ability for foaming, but also taste and odor must be satisfactorily acceptable.
Therefore, there have been conventionally employed anion surface active agents not having taste and odor such as a sodium alkylsulphate, sodium acylsalkosinate, alpha-olefin sulphonate, and a monoglyceride composed of sodium sulphate and a coconut oil, etc.
However, the anionic surface active agents have disadvantages that mucous membrane in mouth is irritated, tastes of foods are changed after using, and an effect by enzymes to be mixed as medicinal components in tooth paste is decreased. Furthermore, safeness has recently become problematic.
In view of situations, anionic surface active agents have advantages of milder irritation to skin and mucous membrane compared to anionic surface active agents. Furthermore, the anionic surface active agents have an advantage of not decreasing the effect by enzymes, and a fatty acid esters composition of sucrose and a fatty acid esters composition of a polyglycerine are narrowly approved as surface active agents for food processing.
Therefore, a fatty acid esters composition of sucrose and a fatty acid esters composition of a polyglycerine are proposed as surface active agents for mixing in tooth paste.
However, a fatty acid esters composition of sucrose and a conventional fatty acid esters composition of a polyglycerine have disadvantages that those do not sufficiently foam in use, and an effect as tooth paste and a feel in use are exceedingly poor. It is only known that monolaurate of sucrose and monomyristate of sucrose were mixed [G. L. Fosol and P. Rovesti, (International Symposium on Sugar-ester) Maison de la Chimie Paris, Jun. 8, 1960].
The problems in the composition for tooth paste can be solved by the use of the fatty acid esters composition of a polyglycerine containing high contents of a fatty acid monoester in the present invention.
As a specific example of cosmetics, a cleaning agent composition is widely used in a variety of fields. Particularly, a cleaning agent composition importantly acts in food industries,
In the food industries, it is used for cleaning foods themselves, starting materials for foods processing, apparatuses for foods processing, and containers such as bottles or cans.
In the food industries, safeness of a cleaning agent composition is severely demanded because it possibly remains in apparatuses, containers, and foods themselves to be cleaned, resulting in that it is taken together with foods or beverages in human body.
Particularly, as a cleaning agent composition for the food industries is often used for foods themselves, there have been used a fatty acid esters composition of sucrose and a fatty acid esters composition of glycerine which are also additives for foods from viewpoint of safeness (Journal of Food Sanitation, vol. 18, No. 3, page 217).
Furthermore, JP-A-158090/1994 discloses that there is used a mixture composed of a monoglyceride composition of a polycarboxylic acid ester and a fatty acid esters composition of glycerine which are ionic surface active agents as a cleaning agent composition. However, the cleaning agent composition in the Journal and the mixture in the JP are not sufficient in cleaning ability.
The problems in the cleaning agent composition can be solved by the use of the fatty acid esters composition of a polyglycerine containing high contents of a fatty acid monoester in the present invention.
The cleaning agent composition of the present invention is harmless for human body and strong in cleaning ability, and it can be preferably used as a cleaning agent composition for foods, starting materials for foods, apparatuses for foods processing, and bottles, containers, and cans in food industries.
As a specific example of cosmetics, a foaming composition for cleaning is widely used as a cleaning agent in cosmetic fields and a detergent for a kitchen or bathroom.
For example, hair washing with a shampoo requires rinsing by water or warmed water after washing. However, in the case when a person cannot have a bath or cannot wash with water because of an injury, or in a place being incapable of using water, it is difficult to clean hair.
Therefore, there is proposed a wiping type cleaning agent which does not require rinsing.
Specifically, there are exemplified an aerosol type water-based cleaning composition in JP-B-47960/1982, a foaming hair cleaning agent in JP-A-289023/1986, a foaming hair cleaning agent for wiping a shampoo in JP-A-205011/1987, a dry hair cleaning method and an agent therefor in JP-A-14711/1988, and an aerosol type shampoo composition in JP-A-190813/1988, etc.
However, conventional compositions in which an electrolyte-based surface active agent is employed are not sufficient in stimulation to head skin and hair by only wiping, and spray-type conventional compositions in which a non-electrolyte-based surface active agent is employed are not satisfied because cleaning agents are scattered beyond necessary portions, and foam-type conventional compositions in which a non-electrolyte-based surface active agent is employed are not satisfied in cleaning ability and refreshing feeling because a mixing amount of alcohols is limited in order to prepare a foam type one.
Furthermore, JP-A-100435/1994 discloses that a non-electrolyte-based surface active agent such as a fatty acid esters composition of a polyglycerine is employed in combination with a higher alcohol to prepare a foaming composition for cleaning containing a large amount of the higher alcohol.
However, the conventional fatty acid esters composition of a polyglycerine is not prepared by the glycidol process (5) as described hereinabove. Accordingly, the content of a fatty acid monoester is low in the composition, resulting in that the foaming composition for cleaning does not satisfactorily exhibit sufficient stability for a long time of period, a cleaning effect, and a refreshing feel.
The problems in the foaming composition for cleaning can be solved by the use of the fatty acid esters composition of a polyglycerine containing high contents of a fatty acid monoester in the present invention.
As a result of an intensive investigation by the present inventors, the present invention has been completed.